A New York judge has given the go-ahead for a group to collectively sue Apple for damages over its collusion with publishers to fix the price of electronic books.

Denise Cote, a judge at the U.S. District Court for the Southern District of New York, wrote in her approval of class status that "Virtually all class members paid inflated prices for e-books as a result of a centralized price-fixing conspiracy."

"If certification were not appropriate here, no antitrust class action could be certified," she wrote.

The case dates back to 2012, when the U.S. Department of Justice and 16 states filed lawsuits against Apple, Hachette Book Group, HarperCollins Publishers, Holtzbrinck Publishers (better known as Macmillan), Penguin and Simon & Schuster, alleging they conspired to keep the price of e-books at a certain level.

The DOJ alleged the six companies worked together to counter Amazon's strategy of reducing the price of new and best-selling e-books to US$9.99.

In 2012, Judge Cote confirmed that assertion and in 2013 Apple appealed her ruling.

In approving the class status, Judge Cote rejected Apple arguments that each e-book purchase is unique and should be heard separately, and that the plaintiffs are not "similar" enough to have their cases heard together.

The case is 11-2293, In Re: Electronic Books Litigation, at the U.S. District Court for the Southern District of New York.